Refrigerating apparatus



March 7, 1933. D E MACCABEE 1,900,510

REFRI GERATING APPARATUS Filed Oct. 30, 1928 2 11M MM 351 W Y M Patented Mar. 7, 1933 UNITED STATES DAVID E. MACCABEE, OF DAYTON, OHIO, ASSIGNOB TO FBIGIDAIBE CORPORATION, 01' i PATENT OFFICE DAYTON, OHIO, A CORPORATION OF DELAWARE REFRIGERATIN G APPARATUS Application filed October 30, 1928. Serial No. 318,005.

This invention relates to refrigerating apparatus and particularly to soda fountains and similar devices in which various commodities of different characters are maintained at different temperatures.

It is one of the objects of the invention to provide a simplified and economical refrigerating system particularly adapted to soda fountains.

Another object of the invention is to provide an improved and simplified arrangement for maintaining a number of different temperatures by means of a single refrigerating system.

More specifically it is one of the objects of the invention to operate a plurality of evaporating elements in series and to provide an improved and simplified means for controlling the amount of liquid refrigerant which enters successive evaporators of the series. 7

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the present invention is clearly shown.

In the drawing:

Fig. 1 is a diagram of a refrigerating system embodying the present invention; and

Fig. 2 is a vertical longitudinal section of a portion of a control device.

It is usual to provide soda fountains with a compartment for storing ice cream which should be kept at a temperature of 7 F. or less, a compartment for storing and coolin water on draft which should be maintaine at a temperature between 35 and 40 and a compartment for containers of fountain syrups, fruit juices and the like, commonly .called a syrup rail. which should be maintained at a temperature between 35 and F.

My invention is concerned with an improved arrangement and method for maintaining the above mentioned compartments at their individual proper temperatures by means of a single refrigerating system or apparatus.

Referring to Fig. 1 any suitable soda fountain is provided with an ice cream storage compartment 11, a water cooling compartment 12 and a syrup rail 13 for holding syrup containers. Each of the compartments may be suitably insulated according to the temperatures at which it is to be maintained. A relatively high pressure evaporator 16 is placed in the water compartment and a relatively low pressure evaporator 17 placed in the ice cream compartment. Preferably the evaporator 17 is immersed in a non-freezing solution such as brine as is usual in cases of this character, and the evaporator 16 is immersed in fresh water. These evaporators are preferably of the flooded type and each includes a header 20 forming a reservoir for liquid refrigerant which is kept at a constant level therein under the control of a float 22, and refrigerant circulating tubes or coils 23. The evaporators are supplied with liquid refrigerant through liquid lines 26 and 27 connected in parallel to a condensing element generally denoted by 28 which, also withdraws evaporated refrigerant from both'said evaporators through a vapor conduit 29.

Refrigerant evaported in the evaporator 16 is withdrawn through a conduit 30 which is ultimately connected to the conduit 29 and which is provided with any suitable pressure regulating shut-off valve 31, the construction of which may be, for example as is illustrated and described in the application of Ernest Dickey, Serial No. 753,- 048, filed December 1, 1924. This valve is opened by the pressure of refrigerant in the evaporator 16 and automatically closes at some predetermined low pressure corresponding, for example, to 35 F. and thus prevents refrigeration of the evaporator below that temperature.

The condensing element 28 includes any suitable compressor 32 actuated by a motor 33 under the control of a switch 34 which is operated in response to the pressure existing in the vapor conduit 29. When the pressure existing in this conduit is above that corresponding to a temperature of about 5 F. the switch closes to actuate the compressor and withdraw the refrigerant from the evaporator 17 until the pressure has been reduced to a value corresponding to a predetermined low temperature, for example zero degrees. Refrigerant is evaporated in and withdrawn from evaporator 16 only when the pressure regulating valve 31 is 0 en, that is, when the temperature of 16 is a ove 35 F.

The conduit 30 connecting the evaporator 16 and the exhaust conduit 29 includes a portion 35 forming an evaporator which is in thermal relation with the syrup rail. In order to supply liquid refrigerant to the evaporator 35, I employ the following device for drawing liquid into the conduit 30 from the header 16 along with the vapor withdrawn from the latter. The header 20 of evaporator 16 is provided with the usual head or end plate 40, secured to the header in any suitable manner, as by bolts passing through holes 41. The head 40 is provided with an inlet 42 and outlet 43 for connection to valves 44 and 45 in the liquid and vapor lines 26 and 30 respectively. Inside the head, and containing the liquid inlet passage 42 is a boss 46 having a small opening 47 for the admission 0 liquid to the header. A tubular support 48 for the float 22 and a needle valve 50 (controlled by the float) is mounted on the boss 46, and is provided with a passage 51 registering with the opening 47 and forming a guide for the valve 50.

A suction tube 52 extends from the outlet 43 into the header, terminating in a horizontal opening 53 above the normal level of liquid in the header. The header normally contains liquid refrigerant to the level 54 and oil to the level 55. At the level 55 an oil drain hole 56 is pierced in the tube 52. Thus refrigerant vapor is withdrawn through the tube 52 from above the liquid level, and oil may drain out of the header whenever it reaches the level 55. A small tube 58 connects with the passa e 51 near the opening 47, and just back 0 the point of the valve 50. This tube terminates within the vapor tube 52. Liquid refrigerant in the inlet 42 is under relatively high pres sure, for example 50 pounds per square inch, while the liquid in the header is under relatively low pressure, for example 9 pounds per square inch. Therefore whenever the float valve opens, liquid flows through the opening 47 and into the passage 51 at high velocity. The body of liquid present in the passage 51 tends to stop this rapid flow of liquid and to convert its velocity head into pressure head. This pressure head is sufficient to cause a certain amount of liquid to flow up through the tube 58 into tube 52. Therefore liquid refrigerant is drawn into the evaporator 35 along with the vapor, and is there evaporated, cooling the syrup rail. Any excess liquid, not evaporated in the portion 35 is collected in the trap 60 to prevent its being returned to the compressor. Such liquid may return to the evaporator 16 thru the drain 62 which must ob viously be provided with a suitable check valve 64 to insure that all refrigerant withdrawn from the evaporator 16 will pass thru 35.

The above described system provides a very simple and reliable method of cooling the syrup rail of a soda fountain and of controlling the amount of liquid refrigerant whichis admitted to the syrup rail evaporator.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming fvithin the scope of the claims which fol- What is claimed is as follows:

1 Refrigerating apparatus comprising a refrigerating element including a reservoir for liquid refrigerant, a second refrigerating element connected in series with the reservoir above the level of liquid therein, and means for delivering liquid from below said level to the connection, including a passage communicating with the reservoir below said level and adapted to be connected to a source of liquid under relatively high pressure, and a conduit leading from said passage into the connection to the second element.

2. Refrigerating apparatus comprising a refrigerating element including a reservoir for liquid refrigerant, a second refrigerating element connected in series with the reser voir above the level of liquid therein, and means for delivering liquid from below said level to the connection, including a passage communicating with the reservoir below said level and adapted to be connected to a source of liquid under relatively high pressure, a valve in said passage, means for opening and closing the valve and a conduit connected to said passage adjacent the valve and leading into the connection to the second element.

3. Refrigerating apparatus comprising a refrigerating element including a reservoir for liquid refrigerant, a second refrigerating element connected in series with the reservoir above the level of liquid therein, and means for delivering liquid from below said level to the connection, including a passage communicating with the reservoir below said level and adapted to be connected to a source of liquid under relatively high pressure, a valve in said passage, means for opening and closing the, valve in response to changes in the level of liquid in the reservoir, and a conduit connected to said passage adjacent the valve and leading into the connection to the second element.

4. Refrigerating apparatus comprising a element connected in series with the reservoir and disposed above the levelof liquid therein, the connection being arranged to deliver both liquid and gaseous refrigerant to the second element, and a drain from the outlet of the second refrigerating element to the first element.

6. Refrigerating apparatus comprising a refrigerating element including a reservoir for liquid refrigerant, a second refrigerating element connected in series with the reservoir and disposed above the level of liguid therein, the connection being arrange to deliver both liquid and gaseous refrigerant to the second element a trap connected to the outlet of the second element, and a drain from the trap to the first element.

7. Refrigerating apparatus comprising in combination a gas and liquid separating chamber; means for maintaining a substantially constant level of li uid therein including an orifice below the evel to be maintained for admitting liquid refri erant from a high pressure source, and a va ve actuated in response to the level of liquid in the chamber for controlling the orifice; and means for delivering liquid from the chamber including a conduit havin its inlet in o n communication with sai body of liqui but disposed adjacent the orifice whereby high veocity regigerant flowing from the orifice into the y of liquid in the chamber will create sufiicient pressure head to force liquid throulgzi said conduit.

8. frigerating apparatus comprising in combination a gas and liquid separating chamber; means for maintaining a substantially constant level of liquid therein including an orifice below the evel to be maintained for admitting liquid refrigerant from a high pressure source a valve actuated in response to the level of liquid in the chamber for controlling the orifice, and a passa leading directl from the orifice into t e main portion 0 the chamber; and means for delivering liquid refrigerant from the chamber including a conduit connected to said )assage whereby high velocity refrigerant flowing from said orifice into said passage will create substantial pressure head to force liquid through the conduit.

9. Refrigerating apparatus including a pair of compartments to be kept 0001, an evaporator in each of the compartments, means for supplying liquefied refrigerant to the first of said evaporators, means for conducting refrigerant from the first evaporator to the second and gravity means including a check valve for returnin a portion 0 the refrigerant dischar ed rom the second evaporator directly to t e first evaporator, sai evaporators and said last mentioned gravity means being maintained at the same pressure.

l0. Refrigerating apparatus including a pair of compartments to be kept cool, an evaporator in each of the compartments, means for supplying liquefied refrigerant to the first of said evaporators, means for conducting liquid and gaseous refrigerant from the first eva rator to the second evaporator, means or conducting refrigerant discharged from the second evaporator to a trap, means for conducting liquid refrigerant collected in the trap to the first evaporator and means for preventing the flow of refrigerant from the first evaporator to the trap through said last mentioned means.

11. Refrigerating apparatus comprising in combination an evaporator including a horizontal passage, a second evaporator below the level of the first mentioned evaporator and including a gas and liquid separating chamber, an outlet conduit connected above the level of the li uid in said second evaporator and connecte to said first mentioned evaporator, means responsive to the level of liquid in the second evaporator for supplying volatile liquid refrigerant into said last mentioned conduit and means for draining liquid refrigerant from said first evaporator and conducting said liquid refrerant to the second evaporator.

n testimony whereof I hereto ailix my signature.

DAVID E. MACCABEE.

III 

